Memory system, personal computer, and method of controlling the memory system

A memory system comprising:

• a nonvolatile semiconductor memory including a plurality of sets of a normal block, which is a unit of data erasing, and a dummy block;
• a writing control unit that rewrites each of the dummy blocks a number of times equal to or larger than a number of times of rewriting of each of the normal blocks;
• a monitor unit that monitors data erasing times or data writing times of the dummy blocks;
• and
• a wear-leveling control unit that averages the numbers of times of rewriting of the normal blocks, wherein
• the memory system determines, based on a monitor result of the monitor unit, possibility of continuation of the rewriting of the normal blocks.

A method of controlling a memory system including a nonvolatile semiconductor memory having a plurality of normal blocks and at least one dummy block, each of the normal blocks being a unit of data erasing, the method comprising:

• rewriting the dummy block a number of times equal to or larger than a maximum number of times among numbers of times of rewriting of the normal blocks;
• monitoring a data erasing time or a data writing time of the dummy block;
• averaging the numbers of times of rewriting of the normal blocks;
• and
• determining, based on a monitor result of the monitor unit, possibility of continuation of the rewriting of the normal blocks.